Powered toothbrushes having replaceable heads are known in the art. Such powered toothbrushes typically include a body and a replacement head that is detachably coupled to the body. The replaceability of the heads in such powered toothbrushes is desirous for several reasons. Different types of replacement heads/brushes with bristles or other cleaning elements having varying features (for example, without limitation, the hardness of bristles, the length of bristles, the thickness of bristles, the profile of bristles, a combination of several kinds and materials of bristles, the cut shape of bristles, the arrangement of bristles) are designed in accordance with specific purposes of different users (for example, without limitation, periodontal pocket care, interdental care, dental plaque removal, gum stimulation, whitening, polishing) and are also designed to meet varying user preferences (for example, mouth feeling at the time of use). Additionally, the body, which includes the motion-inducing circuitry and components, has a longer life expectancy than does the brush part, i.e. the tooth cleaning elements (and other elements) of the head that perform the cleaning work within the oral cavity. The brush part of a replacement brush/head is a consumable. Accordingly, replacement brushes/heads need to be supplied continuously to users (consumers). It would be inconvenient to a consumer if they had to discard the entirety of the powered toothbrush when the tooth cleaning elements (or other elements of the head) wore out. In many instances, a user will purchase several replacement heads/brushes in a year's time if he/she regularly uses an electric toothbrush. Thus, it is has become common in the industry to design the powered toothbrush body and the head portion to be capable of being detachably coupled to one another, thereby allowing the consumer to replace a worn-out or particular head portion with a new or different head portion at the appropriate time.
Examples of a document that discloses a structure of an electric toothbrush include Japanese Laid-Open Patent Publication No. 2011-143057 (Patent Document 1), Japanese Laid-Open Patent Publication No. 2011-139844 (Patent Document 2), and the like. According to a structure of an electric toothbrush disclosed in each of these documents, a replacement brush is attached to an electric toothbrush main body as follows. A protruding part formed in a surface of a stem provided in the electric toothbrush main body is fit into a recessed part formed in an inner circumferential face of the replacement brush, so that the replacement brush is fixed to the stem. In electric toothbrushes, vibrations generated by an electric toothbrush main body should be transmitted efficiently and effectively from the electric toothbrush main body to a brush part of a replacement brush.
Existing replacement heads suffer from a number of deficiencies, including complexity of manufacture of the replacement head, the ability to improperly load the replacement head to the body, and inadequate coupling stability of the replacement head to the body. Thus, a need exists for an improved replacement head, and oral care implement including the same.